One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Lisle you can estimate when it's the best time to plant torenia by using the USDA zone info.

Planting Calendar for Torenia

Frost tolerance for torenia:	Not tolerant of frost.
When to plant:	After the last frost has passed.

It's probably a bad idea to plant torenia until after the last frost when the weather gets warmer because they do not do well in cold weather.

The earliest that you can plant torenia in Lisle is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant torenia and expect a good harvest is probably August. You probably don't want to wait any later than that or else your torenia may not have a chance to grow to maturity. Starting your torenia indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Lisle. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Lisle is an average the actual date of last frost changes from year to year. Half of the time in Lisle you get surprised by a frost after April 15 so make sure that you are ready to protect your torenia in the event of one of those late frosts.

USDA Zone Info for Lisle

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Lisle

You may be interested in your other planting guides for Lisle.